Comparison of the actions of diazepam and lorazepam.

Diazepam and lorazepam differ in potency and in the time-course of their action. As a sedative, diazepam 10 mg is equivalent to lorazepam 2-2.5 mg. Diazepam is better absorbed after oral than after i.m. administrations but this does not apply to lorazepam. The clinical effect and amnesia begin more rapidly with diazepam, but last longer following lorazepam. Lorazepam is more effective than diazepam in blocking the emergence sequelae from ketamine. Lorazepam i.v. is followed by a lesser frequency of venous thrombosis.